Chondrocyte Infiltration and ECM Production on Surface- Treated PCL Scaffolds: Alkaline Hydrolysis versus Plasma Treatment

Abstract

The objective of this study was to comparatively examine the responses of porcine chondrocytes to two different polycaprolactone (PCL) scaffolds whose surfaces were treated by alkaline hydrolysis and low pressure oxygen (O2) plasma treatment, namely HPCL and plasma-treated PCL scaffolds, respectively. The surface morphology and the hydrophilicity of both scaffolds were evaluated by scanning electron microscopy (SEM) and a water contact angle measurement, respectively. The chondrocytes cultured on each scaffold were assessed for their proliferation, cartilage-specific gene expression, cell infiltration, and extracellular matrix (ECM) synthesis after a 21-day culture period. The scanning electron micrographs revealed the increased roughness of both HPCL and plasma- treated PCL scaffolds compared with the untreated PCL scaffold. The measured water contact angle of the plasma- treated PCL scaffold appeared much smaller than that on the HPCL scaffold. The chondrocytes cultured on the HPCL and plasma-treated PCL scaffolds exhibited an insignificant difference in cell proliferation. The expression of type II collagen and aggrecan mRNA found on both surface-treated scaffolds was not much different, either. Nevertheless, the histological results demonstrated that the chondrocytes on the plasma-treated PCL scaffold could more thoroughly infiltrate into the inner parts of the scaffold than those on the HPCL scaffold. Furthermore, a greater ECM production was observed on the plasma-treated PCL scaffold.